Electric furnace.



, VGELKER.

LECTEIC FURNAOB.

PPLIOATIOH TILED AUG. 1909.

Memed Apr. 18, 1911.

mins. um umm. Msn:

AUGUST VOELKER, OF BEUEL, NEAR BONN, GERMANY.

' ELECTRIC EURNACE.

i Specification* of 'Letters Ptent.

Patented'Aprn 1'8, 1911.

Application filed August 13,' 1909.. Serial No. 512584.

T o all whom 'it may -con cem:

a citizen of the Empire of Gennany, residing at. Beuel, near Bonn-On-the-Rh1ne, m the Empire of Germany, have invented a new v and useful Electric Furnace, -'of which the following -is a Specification v All those acquainted with the nature of quartz knowythat there'is a wide difl'erence between Ordinary glass and qna'rtz, which must be taken into Consideration. In an electrio furnace the raw 'quartz (arenaceous quartzquartz-sand) can he turned into a.

v sem-liquid hot state, but it Can never he made to' melt, but will at Once volatilize' the moment that the temperature isfurther" inreased beyond that point at Which the quartz (has. become 'semi-liquidy It is impossible ftorun' molten quartz Ofi from .the ufnace through a tap-hole, and so it is neeessary to take the softened qua'rtzbody for further v treatment Out of the furnacey' after a of the letter-has 'beentaken ofi,

-part My invention relates to improvements 'in eleetrlc furnaces, ,wherebythey are ada-pted to suceessfully turn raw quartz'into a sem liquid hot state and to form bodiessfrom the 1 Close the 'bottom opening 7 of the health 1. The Chief improvem'entconsists in the ellisemi liquid quartz during its discharge.

in contact with both of them, whereby the l ing' the upper pole in the cover of the'hearth duction of the cross sectionof the electric' and m rendering the 'lowerpole movable. so

that it isadapted to normally close the hot tom' opening in the heart-h and to move downward while supporting the body in its -oourse ..of forination from. the' sem-liquid 45.

quartz.

A fourth' improvement 'COIlSlStS In the reconnection in proport ion to that of the two po'les, sothat the maximum heat. is produced in the material in eontaet'with, the eleetric Connection betWeen-the'two p'oles, since this portion' of: the connection presents the maximum resistance to the current in the whole fur-neee.

-A fifth improvement 'oons'ists in the e1n-. e ploym'ent of means for vertiwllyzmoving othe lower pole With. the electrie connection, Be it known that I, VA'UGUST VOELKER,

so that by gr'adually lowering the lower pole the-beat of the eleetric'conneetlon can be increased and distr'ibuted over an increasing surfaeof the mass in the course .of the process;- Other improvements will be hereinafter set forth.

I will now proceed to desonhe. my invention with reference to' the aocompanylng drawing, which represents a vertical longltudnal section through an improved electrie furnace.

-fiThe' furnace proper is shown to consist of ashearth 1 and a Cover 2 of any known con- 'etiuction and to be provided with charging doors 3, 3, through which the raw quartz an he introduced. The furnace pr'oper is' It is shown to be made in one with a Vertical :prismatie' electric Connection 10 of carbon orgraphitewhich is guided in the cavity 11 of an upper pole 12 of carbon or g'raphiteor .top 2 of the furnaee The crosshead 9 'isat-its'ends provided with rollers 13, 13,

which are adaptedto roll on Vertical guides lowerpole 8 and the electri'c Connection 10 areavertically guided. The crosshead '9 is 16, 16 on .a shaft .17, which letter can be turned by means of a hand-Wheel 18 for raising and lowering the ole -8 with the Connection 10. Two weights 19, 19 suspended by cords 20, 20-fro1n the orosshead 9 may help to. pull the latter 'down'ward The lower movable pole 8 is electrcally connected with the already 'mentioned plate fi hy an elastic eonductorfl, which Can -fl low the motion of the pol'e The u'p'per stationary pole 12 is connected by ;a cnductor "22 with thesaid'source of Current,

secure'd in any known manner in the cover ;ferming ,parts of the frame' i, whereby the suspended from the ends of two ropes .14, 1 or' the like passing over pulleys 15, 15 and vfastened with their other ends on' two drums so that the current can passthrough the. two 'L' poles 8,-12 and the connetion 10. Ex

changeable dies 25, 25 of steel or the like are horizontally guided at the bottom of the furnaoe and are' provided with handles 2'6, 26 by 'means of which they can be operated. When by 'means of the hand-Wheel 18 the lower pole 8 has been so much lowered as to be just beneath the dies 25, 25, the latter can bei'plushed inward bytheir handles 26, 26

and w form an annular mouth around the ele'ctric connection 10.

The 'electric furnace is operated as follows: At the commencement the movable pole 8 with the cross-head 9 occupies the uppermost' position shown, so that 'there will be the minimum distance between the lower pole 8 and the lower end face of the upper p0le12 and the connection 10 will present its' minimum sui'face to the raw material introduced. After thecharge of thehea'rth 1- with raw quartz (arenaceous quartz, quartZ-sand-) through the doors 3, 3 the current. is turned on. The part of the connection 10 between the .lower pole 8 and the lower end face of the upper pole 12 having smallest cross section and presenting the maximum resistancexto' the current will be jstrongly heated, so that the raw material surroundin it will soften rapidly and form a body, 'fhen the cross-head 9 1s"pulled downward so much by means of the hand- ,wheel 18, that the dies 25, 25 can be pushed inward bytheirhandles 26, 26 to form the annnlar mouth through which the softened -qu'artz is afterward permitted to issue downward from the hea'rth 1.' When the body 'surroundin the connection 10 has attained a sufiicient y high temperature, the lower .pole .8 is by means of thehand-wheel 18 a little lowered, so as tonncover an increas- 'ingsurface 'of the connection 10, so that the white heatof the part of the connection 10 between the poleswill be distributed over,

'an .increasing quant'ty of the material and the raw quartz surr unding the electric connection 10 between the softened body already formed and the end of the upper pole 12 'will--be'likewise 'softened, and consequently the body 'islengthened. Afterward the lower pole 8 is once'more a little lowered for uncoverin a-further surface of the connection 10, W en a-further quantity of raw quartz will besoftened; In this manner the 'lower pole 8 is gradually lowered for softening a further qua'ntity of the raw quartz, so that a'quart'z tube is .formed on the con- 'nection 10. Whereson preferred, at or shortly before t'he end of the process comeeaevi of formation from the softened quartz and may serve as, a Core, which a't'terward requires to be removed. t

As already mentioned above, the electric connection '10 is guided in the cavity 11 of the upper stationary pole 12, so that it rethe connection 10 has a smaller Cross section and consequently presents a larger electric rcsistance'than the two poles 8 and 12. The connection 10 maybe a round bar, as described above, or it may be a square Or rectangnlar bar or a plate. The lower pole 8 may be made in one with the connection 10, as described above, or it may be made separately and provided with a" central or middle hole or recess for holding and guiding the lower end of the connection 10, or it may, consist of two parallel bars adjoining opposite sides of'the end of the connection 10 and therewith connected in any known manner. The upper stationary pole 12 mw be tubular as described above, or it may consist of two parallel plates between which the electric Connection 10 is vertieally 'uided. The body of quartz to be formed in the electric furnace depends upon the shape of the two poles 8 and 12 and of the electric connect-ion 10 described above.

Of course more than one pair of poles with their electric connection may be disposed in the furnace, if this should be rendered necessary. The sizes of these parts will require to be selected and proportioned in accordance with the obj ects to be 'attained Theelectric :turnace can be varied in many respects without departing from the spirit of my invention.

I claim:

1. In an electric furnace, the combination with a. covered hearth provided with a. bottom opening, of a pendent prismatic pole secured in the cover of said hearth, a movable pole adapted to normally close the bottom opening of said hearth, a Vertical prismatic connection connected with said movable pole and adapted to remain in electric contact with said pendent pole, and means for vertically moving said movable pole, said ver- 'ticaln prismatic connection being of smaller cross section than said two poles.

2. In an electric furnace', the combination With a covered hearth provided with a bottom opening, of a pendent prismatic pole secured in the cover of said hearth, a movable pole adapted to normally close the bottom opening of said hearth. means vertically guidine' 'saidmovable pole, means for moving said movable pole,a Vertical pr'ismatic connection connected with said movable pole and'adapted to remain in electric contact 'cuit including se an with said pendent pole, itbeing of smaller cross section than said two: poles, and a cirsaid two poles and said prismatic Connection. M v In an electric furnace, the combination with-a covered 'hearth provided with a bottom' opening, of a pendent prismatic pole secnred in the cover of said hearth, a movable p'ole adapted to normally close the botw tom opening of said hea'rth, means verticall ry iwith said pendent pole,

4 tom Opening,

guiding said movable pole, means for moving 'said movable pole, a Vertical prismatic connection connected' with said movablenole in electriccontact.

and adapted to remain .it being of sinaller cross section than said two poles means for varying the cross sectional area' of the boti tom opening of said hearth besides: said Ver tical prismatic connection, and a circuit-including said 'connectlon' two polesand said pri'smatic 4. In an electric furnace, the combination with a covered hear-th provided with a bot- O a pendent p'risina tic polesecured in the cover of said hearth and provided with a vertical prisn at-ic cavity, a movable pole adapted to normally close the bottom opening of "said hearth,a Vertical pri'smatic connection 'connected with said movable pole and guided i'n 'the cavity said pendent pole whereby the formation' of 'an' ara is prevented, .it being'of smaller cross section than said' two poles, and means for vertically moving said movable pole.

5. In an electric furnace, the combination with a covered hearth provided with a bottom opening, of a pendent' prismat-ic pole secured in the cover of said hearth and piovided with a Vertical prismatic cavity, a movable pole adapted to normally close the 'bottom opening of said hearth, means vertically gniding said movable pole, means for moving said movable pole, a Vertical prismatic connection connected with 'said movable pole and guided in the cavity of said pendent pole whereby the formation of an are is prevented, said being of smaller cross section than said two moving said movable pole, a Vertical prisablepole and guided in the cavitv of said pendent pole whereby the Ormation of an AUGUST VOELKER.

Witnesses NIKOLAUS MEURER, M. KNnPrERs.

a pendent prismatic 'pole prismatic .connection poles, an d a circuit including said two poles matic connection connected with said movare is prevented, said prismatic Connection varying the cross sectional 

